The present invention is generally related to a rubber composition. More particularly, the present invention is related to a composition comprising a liquid polymer and polymer nanoparticles, which is used to manufacture rubber articles with improved reinforcement and controllable hysteresis.
For rubber articles such as a vehicle tire, important properties such as tread wear/durability, wet/dry traction and rolling resistance can be somewhat determined by the composition of the tread compound. Snow and ice traction (G′ at −20° C.), wet traction (tan δ at 0° C.), and rolling resistance (tan δ at 50° C.) are commonly used in the tire industry to predict tire performance.
Achieving good reinforcement while desirably controlling hysteresis properties is very challenging and demanding. For example, although high levels of aromatic processing oils are normally included in tire tread formulations to increase dry traction characteristics (see U.S. Pat. No. 4,861,131), the aromatic oils can reduce the durability of the tire.
The present invention provides a rubber composition comprising a liquid polymer and polymer nanoparticles. In preferred embodiments, the composition may include less or even no aromatic oil. The composition is extremely useful in manufacturing rubber articles such as tires and power belts with improved properties.